1. Field of the Invention
This invention relates to a video game system for implementing a role-playing game (RPG) in which a player character standing in for the player aims at achieving a certain goal in terms of a story on a video screen, wherein the game is made to proceed by manipulating the character displayed on the screen. The invention further relates to a method of controlling the system and to a memory cartridge for the video game.
2. Description of the Related Art
In a role-playing game, the player aims at achieving a certain goal in a story (searching for a sweetheart who has gone missing because of an accident, searching for a companion who will cooperate with the player, rescuing a city dweller from a disaster, etc.), and the player plays the game by manipulating the player character displayed on the screen.
A role-playing game is characterized in that greater emphasis is placed upon the story than is the case with games of other genre, and that the player plays the role of the hero or heroine (or heroes or heroines) in the story. A background screen of the kind which visually expresses a mythical world is displayed. In the latest examples of such role-playing games, mountains, cities and buildings are displayed, as well as city dwellers walking among them. Besides the player character, a plurality of other characters who become the friend or enemy of the player character appear.
Another characterizing feature of a role-playing game is that the internal data relating to the hero whose role is played by the player has a growth element. The player plays the game by freely making a variety of choices, such as conversing with people, buying and using objects, fighting with an enemy, etc . . . . The choices made are evaluated and the data is internally modified accordingly (mainly in a direction that tends to advance the game).
In a conventional role-playing game, the conduct of the player character is controlled and evaluated by a single predetermined program. These leads to the following problems:
First, the story lacks a sense of surprise. Specifically, while the player is moving the player character, which is the player's own character, the other characters are at rest on the screen or merely perform fixed actions (such as moving back and forth) in accordance with a simple display processing routine or actions that are based upon random numbers.
Second, the program is made complicated by a diversity of conditional branch statements. When, in order to provide a story with a greater sense of surprise, it is attempted to cause the other characters to perform meaningful actions while the player character is being moved, a variety of conditional branch statements (e.g., an "if.about.else" statement or "switch.about.case.about.case" statement in C language) must be used in the program (an account of all possible cases must be described in the program). This results in a complex game program.